System and method for organizing data stored in a log structured array

A data storage system for storing electronic data for a data processing system, the data storage system comprising:

• an array of storage devices, each storage device comprising a storage media for storing sectors of electronic data;
• a plurality of neighborhoods in destage, wherein each neighborhood in destage comprises a set of related logical tracks in a memory to be destaged to the storage devices;
• and
• a plurality of segments striped across the storage devices in columns, wherein logical tracks of the same neighborhood in destage are assigned to a single segment and when possible all logical tracks of a neighborhood in destage are assigned to a single segment column.

A data storage system for storing electronic data for a data processing system, the data storage system comprising:

• an array of storage devices;
• a processor;
• a memory, coupled to the processor and storage devices, the memory having a plurality of logical tracks to be destaged to the storage devices in segments striped across the storage devices in columns;
• means for identifying an open segment with sufficient available free space to store a neighborhood in destage of logical tracks by traversing a list of open segments;
• means for attempting first to store all of the logical tracks of the neighborhood in destage in the same segment column of the identified open segment;
• means for determining when to split a neighborhood in destage between a plurality of segment columns when disk utilization and memory criteria are met;
• means for writing to the storage devices a segment when the segment has a closing threshold number of sectors assigned to logical tracks;
• and
• means for writing to the storage devices a segment having a capacity threshold number of assigned logical tracks.

An article of manufacture for use in storing and managing a plurality of sets of logical tracks in a computer system having a processor, memory and a group of storage devices, wherein each set of logical tracks in the memory being destaged together to the storage devices is assigned to a segment striped across the group of storage devices in columns, the article of manufacture having a computer program code embodied in said medium which causes the computer system to:

• update a logical track in a segment stored on the storage devices in a first location by writing the updated logical track as part of a different segment to a new storage location, wherein the logical track in the first location is designated an old data block and the logical track in the new location is designated a current logical track;
• identify an open segment with sufficient available free space to store a neighborhood of logical tracks to be destaged by traversing a list of open segments;
• attempt first to store all of the logical tracks of the neighborhood in destage in the same segment column of the identified open segment;
• and
• write an open segment to the storage devices having a threshold percentage of assigned logical tracks.